Orogenic greenstone gold deposits hosted in a number of different styles of lodes. The Granny Smith lodes comprise vein stock works localised by a northerly trending shear at the margin of a granodiorite. The Wallaby lodes are flat lying alteration zones hosted within magnetite amphibole altered conglomerate.

The Granny Smith region is dominated by the Mt Margaret Dome in the northwest and the Kirgella Dome in the southeast. These domes are flanked to the east and west by north-northwest striking shear zones, with the central zone between the two domes being dominated by north to northnortheast-striking sigmoidal shear zones. These distinctly different strikes to the shear zones developed early in the tectonic evolution and resulted in a favourable architecture for late-stage orogenic gold mineralisation at Wallaby and Granny Smith.

The majority of gold mineralisation at the Wallaby deposit is contained within an actinolite-magnetite alteration pipe. It cross cuts the host conglomerate and the majority of magmatic intrusions, and overprints the actinolite-magnetite alteration. Gold occurs along micro-fractures within pyrite.

The current operations consist of the Wallaby underground mine with mining occurring on four ore zones (Z70, Z80, Z90 and Z100).

Access to the Wallaby underground mine is via a portal established within the completed Wallaby open pit. The mine operation is trackless, with truck haulage from underground via the pit ramp to the surface. The Wallaby underground mine is currently designed to exploit lodes to a depth of 1.2km.

Two primary underground mining methods are used, with minor adjustments to suit localised geometry. Inclined Room and Pillar (IRP) is used in areas with a moderate dip (10° to 35°) and moderate width zones (4m to 6m), and transverse long-hole stoping (TLHS) is used in zones, which are thicker (6m to 15m) with variable dips. Two other mining methods are used to a lesser extent: narrow vein long-hole stoping may be utilised in some areas with the benefit of reduced planned footwall dilution, and bulk long-hole stoping is used in thicker zones (15m plus) under varying dip conditions.

A processing plant with a capacity of 3.5Mtpa consisting of two stage crushing circuit, a standard SAG and Ball mill (SABC) grinding circuit, a gravity circuit, a Leach/Carbon in Pulp (CIP) train, a pressure Zadra elution circuit, a tailings recovery (TR) circuit and a thickened tailings storage facility (TSF). However, it is mine constrained and currently operates at 1.5Mtpa on a campaign milling basis.